The aim of this work was to determine the most suitable temperature for rearing Spodoptera frugiperda (J. E. SMITH, 1797) in artificial diet, by means of measuring food consumption and utilization. Fifty larvae were individualized in glass containers of 2.5 cm in diameter x 8.5 cm in height in climate chamber, at 25 ± 1ºC and 28 ± 1ºC temperature with 70 ± 15% relative humidity and 14 hours of photophase. Based on dry matter, were determined the dry weight of the larvae at maximum development, of the food consumed and of the feces eliminated, and the nutritional ratios were calculated: relative consumption ratio (RCR), relative metabolic ratio (RMR), relative growth ratio (RGR), approximate digestibilidade (AD), efficiency of conversion of ingested food (ECI) and the efficiency of conversion of digested food (ECD). Considering that weight of larvae in maximum development was similar in two temperatures, at 28ºC were a larger ECI and ECD and lower 100-ECD, consequently, the larvae of S. frugiperda consumed a lower amount of food reducing the duration of larval phase. Thus, in laboratory, the temperature of 28ºC demonstrated to be the most appropriate for rearing of S. frugiperda in artificial diet.